Y10 Lesson 1.5 Forces in Motion

Multiple Choice

The force between the phone and the mount is a

• contact force

• non-contact force

Multiple Choice

A man pushes a box across the floor at a constant velocity. There is a force on the box from the floor pushing the box up. This is the ...

• force of gravity

• normal force

• force of friction

• applied force

Multiple Choice

The force that acts in the opposite direction of motion when two surfaces come in contact. 

• Force
• Friction
• Static
• Kinetic 

Multiple Choice

Name the missing force...

• thrust
• frictional force
• normal force
• weight force

Multiple Choice

_____________ friction acts on objects that are not moving.

• sliding

• rolling

• static

• fluid

Multiple Choice

This photo represents...

• Air resistance

• water resistance

• friction force between 2 solid bodies

Multiple Choice

Which kind of friction applies to moving (sliding) objects?

• Kinetic friction

• Static friction

Multiple Choice

What force is acting on the rope?

• gravity

• push

• friction

• tension

Multiple Choice

State of a body when external forces are applied to it by rope, cable, or other connection.

• Normal force

• Elasticity

• Tension

• Push or pull

Multiple Choice

What will an object placed in a fluid do if its weight is equal to the upthrust?

• Float

• Sink

• Dissolve

• Expand

Categorize

Options (10)

Throwing a frisbee

Sliding a book across a table

Pressing a button on a remote control

Gravity pulling an object downward

Magnetic force between two magnets

Air resistance

Electrostatic force between charged objects

Magnetic field around a current-carrying wire

Radiation pressure from sunlight

Upthrust

Are these forces examples of contact forces or non-contact forces?

Contact Force

Non-Contact Force

Let's look at the forces acting on an box sitting on a table.

• ​This box is sitting at rest.

• The force of gravity is equal to the normal force.​

• Normal Force - the force that a surface exerts on an object that is pressing on it.​

• The normal force is equal and opposite to the force pressing the object into the surface.

The book is not moving, so the forces must be equal.

• When the forces being applied to an object are equal, the object isn't moving.

• This means that these are Balanced Forces.

• Balanced Forces - forces that result in a net force (total force) of zero.​

When forces are balanced, their NET force is zero. This means the object is in equilibrium.

• Equilibrium - the state in which the net force on an object is zero.

• If the object is not in equilibrium. The object will move!

Multiple Choice

Is this a balanced force?

• Yes

• No

Draw

Circle the guy who successfully pushes the box.

Forces are not just defined by how strong they are but the direction they are moving.

• ​Forces are vectors, which means it has both a magnitude (strength) and direction.

• You will always describe a force with its strength and direction.

• Vector - a quantity that has both a magnitude and direction.​

Fill in the Blanks

Multiple Choice

For free-body diagram in the picture, state whether its in equilibrium. If not, state the direction of acceleration

Multiple Choice

What is a free-body diagram?

• It is a free diagram

• Is a diagram that shows all the forces acting on an  object!

• Is a diagram that shows all kittens acting on an object

​The sum of all the forces acting on an object is called the NET FORCE.

Multiple Choice

What is the resultant force when two forces of 200N are applied in the same direction?

• 200N

• 300N

• 400N

• 500N

Multiple Choice

What are the two main effects of unbalanced forces on an object?

• They can make an object speed up or slow down

• They can change the color of an object

• They can make an object disappear

• They can change the temperature of an object

Multiple Choice

What does the equation F_net = ma represent in terms of force, mass, and acceleration?

• The relationship between force and mass only

• The relationship between mass and acceleration only

• The relationship between force, mass, and acceleration

• The relationship between acceleration and force only

Multiple Choice

According to the diagrams, how does the mass of an object affect its acceleration when the same force is applied?

• Larger mass results in larger acceleration

• Smaller mass results in larger acceleration

• Mass has no effect on acceleration

• Acceleration is constant regardless of mass

Multiple Choice

If a 10 kilogram object accelerates suddenly at 15 m/s², how much force was applied to the object?

• 150 Newtons

• 15 Newtons

• 150 kilograms

• 100 kilograms